In die stamping and the like wherein a pair of spaced apart die members are mounted for relative movement toward and away from one another to form a workpiece between the dies, it is common to provide a die cylinder and manifold system which includes a plurality of die cylinders having piston rods that function to yieldingly resist movement of the die members.
Such systems are shown, for example, in U.S. Pat. Nos. 3,947,005, 4,044,859, 4,342,448, 4,529,181, 4,583,722 and 4,628,796.
Such systems have been utilized at relatively high gaseous pressures up to about 1000 p.s.i.
Among the objectives of the present invention are to provide a die cylinder and manifold system which will function higher pressures on the order of 2000 p.s.i.; which at relatively higher pressures on the order of 2000 p.s.i. ; which will be effective for a long periods of time without leakage; which include a novel lubricating system; which does not require any parts that are more expensive than have been used for systems that function at lower pressures; and to provide a lubricating system for die cylinders which are used in a manifold system or are self-contained.
In accordance with the invention, a high pressure die cylinder and manifold system comprising a plurality of die cylinders mounted on manifold. Each die cylinder includes a cylinder body in which a piston rod is positioned for limited relative movement with respect to the cylinder body. A cup shaped piston sealing ring is mounted on the cylinder body for engagement with the piston rod and a cup shaped sealing ring is mounted on the piston for engagement with the cylinder body. A lubricant metering ring is mounted on the piston intermediate the sealing rings and the piston has a lubricant chamber that communicates with circumferentially spaced openings in the lubricant metering ring for delivering lubricant to the exterior of the metering ring. The cylinder body is provided with a radial annular flange, a cylindrical pilot surface and a portion below said pilot surface of the cylinder body is threaded by interengaging threads with an opening in the manifold so that the lower end of the gas cylinder communicates with high pressure gas within the manifold. The manifold is provided with an annular seat surrounding the opening into which the gas cylinder extends and a U-shaped cup manifold sealing ring is provided in the shoulder and held into position by engagement of the radial flange and a pilot surface on the cylinder body with the manifold.
The above described die cylinder includes a novel lubricating system which can also be used in die cylinders that are used in a manifold system or are self-contained.